The Structure of the Nucleon 3 decades of investigation 1973-2004 - a personal perspective Arie Bodek, University of Rochester Madison, Wisconsin - Sept. 8, 2004

1
The Structure of the Nucleon3 decades of
investigation1973-2004 - a personal
perspectiveArie Bodek, University of
RochesterMadison, Wisconsin - Sept. 8, 2004
2

• Particle Physics pre -1968 simplistic view
• Many different models for Hadron Structure.
• Quarks was considered more of a convenient way to
  model a symmetry rather than real particles
  (since none were ever observed and they had
  strange properties like 1/3 charge.
• Real Particle Physics done in hadron (proton)
  machines where Resonances and new particles
  were being studied and discovered (spectroscopy,
  group theory, partial wave analysis, resonances,
  Regge poles etc.

• Short Interlude quarks discovered in electron
  scattering

• Particle Physics post 1973 simplistic view
• J/psi-Charm and then Upsilon-Bottom discovered
  ee-, p-p
• Real Particle Physics now done at ee- or hadron
  machine where new charm and bottom mesons and
  hadrons are discovered and studied, but now they
  are made of quarks (spectroscopy, partial wave
  analysis, resonances etc.).

• Particle Physics Now simplistic view - Real
  Particle Physics done at ee- or hadron machine
  where new particles are NOT discovered
  (Supersymmetry, Lepto-quarks, Higgs, Heavy
  Leptons etc.

3
The Structure of the Nucleon3 decades of
investigation1973-2004a personal perspective
In the beginning there was hadron Spectroscopy
and quarks were only mathematical objects
and then came the MIT-SLAC electron scattering
experiments 1967-1973
And Quarks became Real Particles
by 2000 Nucleon Structure is well understood and
NNLO QCD works from Q21 GeV2 to the highest
values currently accessible in hadron colliders.
How did we get there?
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by 2000 Nucleon Structure is well understood and
NNLO QCD works from Q21 GeV2 to the highest
values currently accessible in hadron colliders.
How did we get there?

• Like the majority of advances in High Energy
  Physics, progress in this area was accomplished
  by
• Higher Energies (new accelerators and machines)
• And more importantly in combination with
• New experimental techniques - Higher Precision
  To go beyond the Limitations/Brick Walls of old
  techniques
• Better understanding (new theoretical tools)
• Higher Luminosities (more statistics)
• Different probes (new beams)

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Gluons (bosons) field particles of the color
force
Quarks (Fermions) - close to massless (MeV range)
1 GeV Mass
If you want to be fussy, there are also a few
photons from the electromagnetic interaction
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Inclusive e p ? e X scattering
Quarks are spin 1/2
Where

Virtual photons are spin 1 and have mass q2.
Alternatively
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Inclusive e p ? e X scattering
Single Photon Exchange
Resonance
Elastic
DIS
Where

At high Q2 -gt FL 0 for spin 1/2 partons
(virtual photon has spin 1, leading to a spin
helicity flip)
Alternatively
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Why do theorists like this experiment so much? -
Victor Weisskopf
Prelude SLAC MIT 1968-1974
Because they can understand the experimental
setup- it is one of the few experiment where the
apparatus and Feyman diagram look the same
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MIT SLAC e-p DATA 1970 e.g. E0 4.5 and 6.5 GeV

• V. Weisskopf (former faculty member at
  Rochester and at MIT when he showed these data at
  an MIT Colloquium in 1971 ( died April 2002 at
  age 93) Said

• e-P scattering A. Bodek PhD thesis 1972
• PRD 20, 1471(1979) Proton Data
• Electron Energy 4.5, 6.5 GeV Data

The Deep Inelastic Region is the Rutherford
Experiment of the proton. The electron
scattering data in the Resonance Region is the
Frank Hertz Experiment of the Proton.
What do The Frank Hertz and Rutherford
Experiment of the proton have in common?
A Quarks! And QCD
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• A Nobel Prize 1990 - Friedman, Kendall, Taylor
  for their pioneering investigations concerning
  deep inelastic scattering of electrons on protons
  and bound neutrons, which have been of essential
  importance for the development of the quark model
  in particle physics. (1967-73)

Described in detail in"The Hunting of the Quark,"
(Simon Schuster) Michael Riordan AIP Science
Writing Award 1988 AIP Andrew Gemant Award 2003
Important to share the excitement of science
with the public
Front row Richard Taylor, Jerome Friedman, Henry
Kendall. Second row Arie Bodek, David Coward,
Michael Riordan, Elliott Bloom, James Bjorken,
Roger (Les) Cottrell, Martin Breidenbach,
Gutherie Miller, Jurgen Drees, W.K.H. (Pief)
Panofsky, Luke Mo, William Atwood. Not pictured
Herbert (Hobey) DeStaebler Graduate
students in italics
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• 1968 - SLAC e-p scaling gt Point like Partons in
  the nucleon
• 1970-74 - Neutron/Proton ratio - Partons are
  fractionally charged (quarks)

• COMPARISONS OF DEEP INELASTIC ep AND en
  CROSS-SECTIONS AB et al Phys. Rev. Lett. 30
  1087,1973. (SLAC Exp. E49 PhD thesis)-First
  result Next Step higher precision
• THE RATIO OF DEEP - INELASTIC en TO ep
  CROSS-SECTIONSINTHE THRESHOLD REGION AB et al
  Phys.Lett.B51417,1974 ( SLAC E87)

PRL referees - nothing substantially new over
1973
N d d u sea 1/3 1/3
2/3 P u u d sea 2/3
2/3 1/3 Large x N/P -gt 0.25 Explained by valence
d/u PARTONS ARE QUARKS !
(1/3) / (2/3)2 1/4 Small x N/P1
explained by sea quarks
F2N F2P
Scaling-gt Point like PARTONS
2/3
F2P
1/4
1
2
x
x
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• R?L/ ? T (small) quarks are spin 1/2 !
• EXTRACTION OF R ?L/?T FROM DEEP INELASTIC eP
  AND eD CROSS-SECTIONS. E. Riordan, AB et al
  Phys.Rev.Lett.33561,1974.
• EXPERIMENTAL STUDIES OF THE NEUTRON AND
  PROTONELECTROMAGNETIC STRUCTURE FUNCTIONS. AB et
  al Phys.Rev.D201471-1552,1979.

RP
3
BUT what is the x and Q2 Dependence of R? What is
x, Q2 dependence of u, d, s, c quarks and
antiquarks?
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4. Integral of F2(x) 0.5 did not add up to 1.0.
Missing momentum attributed to gluons. Like
Paulis missing energy in beta decay attributed
to neutrinosGluons were Discovered in 1970,
much before PETRABUT what is their x
Distributions?
F2P
4
F2N
5. Scatter shows F2(x, Q2) as expected from
bremstrahlung of gluons by struck quarks in
initial of final states. BUT QCD NOT FULLY
FORMALIZED YET
F2D
5
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Scaling violations from quark binding effects
(Higher Twist, Target mass) go like powers in 1/Q2
QCD scaling violations from gluon emission are
logarithmic with Q2
15

• Next Higher Precision First observation of
  Scaling Violations SLAC
• E. M. Riordan, AB et al TESTS OF SCALING OF THE
  PROTON ELECTROMAGNETIC STRUCTURE FUNCTIONS
  Phys.Lett.B52249,1974 (more detail in AB et al
  Phys.Rev.D201471-1552,1979

Scaling violations SEEN in 1974, Are they
deviations from Parton Model e.g. from gluon
emission, or are they just at Low Q2
F2P Extracted from Rosenbluth separations
Note in 2000. We show that Higher Twist come from
Target Mass NNLO QCD STUDIES OF HIGHER
TWIST AND HIGHER ORDER EFFECTS IN NLO AND NNLO
QCD ANALYSIS AB, UK Yang. Eur. Phys. J. C13
(2000) 241 245.
1974 PRL Referees - obviously these are
uninteresting low Q2 effects
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"Physics is generally paced by technology and
not by the physical laws. We always seem to ask
more questions than we have tools to answer.
Wolfgang K. H. Panofsky

• Questions in 1972-2000 Anti-quarks, strange ,
  charm quarks in nucleons , individual PDFs
  (u,d,qbar,gluons Q2,x dependence) R
  longitudinal structure function (x,Q2), quarks in
  nuclei , origin of scaling violations- low Q2
  higher twist or QCD?,

• A Detailed understanding of Nucleon Structure
  Required Initiating Measurements at Different
  Laboratories, New Detectors, New Analysis
  Techniques and Theoretical Tools - AND also
  sorting out which experiments are right and which
  experiments are wrong - incremental but steady
  progress.

Meanwhile the J/Psi was discovered in 1974 ---gt
and the age of Spectroscopy returned and then
came the Upsilon and there was more spectroscopy
to be done. - but a few people continued to
study the nucleon.
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How are Parton Distributions (PDFs) Extract from
various data at large momentum transfer (e/?/?
and other expts.)
PDF(x)
Valence and sea
H and D
d/u
Also Drell Yan, jets etc
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• Also thanks to our Collaborators over the past
  3.5 decades FUTURE
  ( Blue
  awarded Panofsky Prize)
• The Electron Scattering SLAC-MIT collaboration at
  SLAC End Station A (E49, E87)
  with Kendall, Friedman, Taylor, Coward,
  Breidenbach, Riordan, Elias,
  Atwood others (1967-1973)
• The Electron Scattering E139, E140, E140x, NE8
  collaboration at SLAC ESA/ NPAS injector at SLAC
  (with Rock, Arnold, Bosted, Phillipone, Giokaris
  others) (1983-1993)
• The E379/E595 Hadronic Charm with Barish,
  Wojcicki, Merrit. Fisk, Shaevitz others)
  Production collaboration at Fermilab lab E
  (1974-83)
  
• The AMY ee- Collaboration at TRISTAN/KEK (with
  Steve Olsen others) (1982-1990)
• The CCFR(W)-NuTeV Neutrino Collaboration at
  Fermilab Lab E (with (1974-2004)
  Barish, Sciulli, Shaevitz, Fisk,
  Smith,Merritt, Bernstein, McFarland and others)
• The CDF proton-antiproton Collaboration at
  Fermilab (1988-
• And in particular I thank the graduate students
  and 2004)
• postdocs over the years, and Rochester Senior
  Scientists Budd, deBarbaro Sakumoto.
• more progress to be made with collaborators at
  the CMS-LHC experiment,(1995--gt)
• The New Electron Scattering JUPITER
  Collaboration at
• Jefferson Lab, the new MINERvA Neutrino
  (1993--gt
• Collaboration at Fermilab (McFarland, Morfin,
  Keppel, Manly),

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Fermilab CCFR/NuTeV v-N Expt. ?-N (data) CDF
Collider Expt MINERvA Expt
KEK AMY _at_ TRISTAN JHF
Conclusion
CERN ?-N, v-N (data) CMS Collider
Rochester
J-lab e-N (Data) JUPITER Expt.
SLAC ESA SLAC NPAS programs e-N Data
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• Caltech (-gtColumbia)- Chicago - Fermilab -
  Rochester -(Wisconsin)
• The CCFR(W)-NuTeV Neutrino Collaboration at
  Fermilab Lab E (1974-2004) - separate quark
  and antiquark distributions, Valence and Sea
• Barish, Sciulli, Shaevitz, Fisk,
  Smith,Merritt, Bernstein, McFarland and others)
• .
• Budd, deBarbaro Sakumoto
• Rochester Senior Scientists

V-A Weak Interaction gt difference between quarks
and anti-quarks (Neutrinos are left handed and
antineutrinos right handed)
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Neutrino physics is information rich
NC- Electroweak
CC- quarks antiquarks, PDFs and QCD
dimuons- Charm and Strange quarks
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Neutrino Experiments REQUIRE good Hadron
Calorimetry and Muon Energy calibration (0.3)
10 cm Fe Sampling, NuTeV simultaneous neutrino
running and hadron and muon test beams D.A.
Harris (Rochester), J. Yu et al NuTeV PRECISION
CALIBRATION OF THE NUTEV CALORIMETER. UR-1561
Nucl. Inst. Meth. A447 (2000) W.K. Sakumoto
(Rochester), et al. CCFR CALIBRATION OF THE CCFR
TARGET CALORIMETER.Nucl.Instrum.Meth. A294179-19
2,1990. CCFR Developed Fe-scintillator
compensating calorimeter. 3mx3m large counters
with wavelength shifting readout
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. CCFR(W) Neutrino detector used as a final
state muon identifier in a high energy proton
beam - what is the origin of prompt muon
productxion in hadronic collision PN-gt D--gt
Muon 30 and PN - gt Dimuons 70
B Hadronic Charm Production - Lab E Fermilab
E379/E595 Single muons from charm, dimuons from
Drell-Yan, vary target density to determine rate
of muons from pion decays (1974-1983)
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B Hadronic Charm Production -Lab E Fermilab
E379/E595 Single muons from charm, dimuons from
Drell-Yan, vary target density to determine rate
of muons from pion decays (1974-1983

• Hadronic Charm Production is about 20 mb.
  Distribution is peaked at small Feynman x and is
  dominated by quark-quark and gluon-gluon
  processes. No Intrinsic Charm quarks in the
  nucleon - in contradiction with ISR results.
• Intrinsic C(x) 0

Jack L. Ritchie, HADRONIC CHARM PRODUCTION BY
PROTONS AND PIONS ON IRON. UR-861 (1983) Ph.D.
Thesis (Rochester). Dexter Prize, U of Rochester
- Now Professor at UT Austin
B Are there charm quarks in nucleon ?
25
C Strange Quarks in the Nucleon -
Caltech-Fermilab --gt CCFR (Columbia
-Chicago-Fermilab-Rochester) and -Later- NuTeV
Neutrino Collaborations at Fermilab LAB E.
Dimuon event
K
The Strange Sea Anti-quarks are about 1/2 of the
average of u and d sea - i.e Not SU3 Symmetric.
Karol Lang, AN EXPERIMENTAL STUDY OFDIMUONS
PRODUCED IN HIGH-ENERGY NEUTRINO INTERACTIONS.
UR-908 (1985) Ph.D. Thesis (Rochester) Now
Professor at UT Austin Most recently M.
Goncharov and D. Mason (NuTeV PhDs)
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Precision High Statistics Neutrino Experiments at
Fermilab - Valence, Sea, Scaling Violations,
gluons F2 xF3 , Precise ?s GLS sum rule (Q2
dependence)
GLS( q2) dependence ?s
W.G. Seligman et al. (CCFR Columbia PhD),
IMPROVED DETERMINATION OF ?S FROM NEUTRINO
NUCLEON SCATTERING. Phys. Rev. Lett. 79 1213
(1997)
H. Kim (CCFR Columbia PhD) D.Harris (Rochester)
et. al. MEASUREMENT OF ?S (Q2) FROM THE GROSS-
LLEWELLYN SMITH SUM RULE. Phys. Rev. Lett. 81,
3595 (1998)
27
Precision Neutrino Experiments CCFR/NuTeV Un Ki
Yang UR-1583,2000 Ph.D. Thesis, (Rochester)
Lobkowicz Prize, U of R URA Best Thesis Award
Fermilab 2001 (now at Univ. of Chicago) Un-Ki
Yang et al.. MEASUREMENTS OF F2 AND XF3 FROM
CCFR ?-FE DATA IN A PHYSICS MODEL INDEPENDENT
WAY. By CCFR/NuTeV Phys.Rev.Lett.86, 2742,2001
Same PDFs should describe all processes
Resolved 10 to 20 difference between ? and ?
data
Experiment vs Theory Ratio of F2 (neutrino)/F2
(muon)
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A lot of other physics (not related to nucleon
structure) was investigated in the lab E E595
hadron program and the Lab E CCFR (W) /NuTeV
Neutrino Program --- a few examples

• Some discoveries and precise measurements e.g.
• Neutral Currents and electroweak mixing angle,
  Trimuons (CCFR(w)/NuTeV)
• And also searches and limits (A few
  non-discoveries)
• Limits on Dzero to Dzero-bar mixing (E595)
• Search for New Heavy Leptons Pawel de Barbaro,
  Rochester PhD Thesis 1990
• Search for inclusive oscillations of muon
  neutrinos - Ian Stockdale, Rochester PhD Thesis
  1984
• Search for exclusive oscillations of muon
  neutrinos to electron neutrinos Sergei
  Avvakumov, Rochester PhD Thesis 2002

29
D Quark Distributions in Nuclei - New Parallel
Program at SLAC AB, J Ritchie FERMI MOTION
EFFECTS IN DEEP INELASTIC LEPTON SCATTERING FROM
NUCLEAR TARGETS, Phys.Rev.D231070,1981
Phys.Rev.D241400,1981. 1983 (conference
proceeding) surprising report of difference
between Iron and Deuterium muon scattering data
from the European Muon Collaboration (EMC)
Disagreement with Fermi Motion Models.
Physics Archeology - Use 12 and 13 year old SLAC
Empty target data to check on this
AB, EMPTY TARGET SUBTRACTIONS AND RADIATIVE
CORRECTIONS IN ELECTRON SCATTERING EXPERIMENTS,
Nucl. Inst. Meth. 109 (1973). - factor of 6
increase in rate of empty target data by making
empty target same radiation length as H2 and D2
targets - used in SLAC E87 - more payoff later
ELECTRON SCATTERING FROM NUCLEAR TARGETS AND
QUARK DISTRIBUTIONS IN NUCLEI. AB et al
Phys.Rev.Lett.501431,1983.. - Use Empty Target
Data from SLAC E87 (1972)(initially rejected by
Phys. Rev, Letters) IRON A COMPARISON OF THE
DEEP INELASTIC STRUCTURE FUNCTIONS OF DEUTERIUM
AND ALUMINUM NUCLEI. AB et al Phys.Rev.Lett.51534
,1983. Use empty target data from SLAC
E49B (1970) ALUMINUM
30
Quark Distributions in Nuclei AB et al Phys. Rev.
Lett. 51 534, 1983 (SLAC Expt. E49, E87 empty
tgt data 1970,1972)
EMC
PRL Referees (1) How can they claim that there
are quarks in nuclei (2) Obviously
uninteresting multiple scattering of electrons
in a nucleus- --gt later accepted by PRL editors.
31
D. Back to SLAC using High Energy Beam and the
Nuclear Physics Injector NPAS - SLAC E139, E140,
E140x, E141, NE8 R.G. Arnold et al.,
MEASUREMENTS OF THE A-DEPENDENCE OF DEEP
INELASTIC ELECTRON SCATTERING FROM NUCLEI
Phys. Rev. Lett.52727,1984 (initial results
incorrect by 1 since two photon external
radiative corrections for thick targets not
initially accounted for. Found out later in SLAC
E140) J. Gomez et al., MEASUREMENT OF THE
A-DEPENDENCE OF DEEP INELASTIC ELECTRON
SCATTERING. Phys.Rev.D494348-4372,1994.
Back to SLAC End Station A to measure effect on
various nuclei
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1983 The field of quark distributions in
nuclei hit a brick wall The issues (1) Precise
Values and Kinematic dependence of R needed to
extract F2 from all electron muon and neutrino
experiments. (2) Precise normalization of F2
needed to establish normalization of PDFs for all
DIS experiments to 1. Solution--gtSLAC E140 -
SLAC E140, E140x - . New Precision Measurement
of R and F2, and Re-Analysis of all SLAC DIS
data to obtain 1 precision.

• New hardware, new theoretical tools 1 month run
  worth years of data, IMPACT all DIS Experiments
  Past and Future.
• Upgrade Cerenkov Counter for ESA 8 GeV
  spectrometer - N2 with wavelength shifter on
  phototube
• Upgrade Shower Counter from lead-acrylic (to
  segmented lead glass)
• Upgraded tracking (wire chambers instead of
  scintillator-hodoscope)
• Upgraded Radiative Corrections - Improved
  treatment using Bardin, Complete Mo-Tsai, test
  with different r.l. targets ( to 0.5)
• Cross normalize all previous SLAC experiment to
  SLAC E140 by taking data in overlap
  regions.(Re-analysis with upgraded rad corr).

33
Sridhara Rao Dasu, PRECISION MEASUREMENT OF X, Q2
AND A-DEPENDENCE OF R ?L/?T AND F2 IN DEEP
INELASTIC SCATTERING. UR-1059 (Apr 1988) . Ph.D.
Thesis. (Rochester) SLAC E140 - winner of the
Dexter Prize U of Rochester 1988 (now on the
faculty at U. Wisconsin, Madison) S. Dasu
(Rochester PhD )et al., MEASUREMENT OF THE
DIFFERENCE IN R ?L/?T, and ?A/?D IN DEEP
INELASTIC ed, eFE AND eAuSCATTERING.
Phys.Rev.Lett.602591,1988 S. Dasu et al.,
PRECISION MEASUREMENT OF R ?L/?T AND F2 IN
DEEP INELASTIC ELECTRON SCATTERING.
Phys.Rev.Lett.611061,1988 S. Dasu et al.,
MEASUREMENT OF KINEMATIC AND NUCLEAR DEPENDENCE
OF R ?L/?T IN DEEP INELASTIC ELECTRON
SCATTERING. Phys.Rev.D495641-5670,1994. L.H.
Tao (American U PhD) et al., PRECISION
MEASUREMENT OF R ?L/?T ON HYDROGEN, DEUTERIUM
AND BERYLLIUM TARGETS IN DEEP INELASTIC ELECTRON
SCATTERING. Z.Phys.C70387,1996 L.W. Whitlow
(Stanford PhD), et al. , A PRECISE EXTRACTION OF
R ?L/?T FROM A GLOBAL ANALYSIS OF THE SLAC
DEEP INELASTIC ep AND ed SCATTERING
CROSS-SECTIONS. Phys.Lett.B250193-198,1990.
L.W. Whitlow, et. al., PRECISE MEASUREMENTS OF
THE PROTON AND DEUTERON STRUCTURE FUNCTIONS FROM
A GLOBAL ANALYSIS OF THE SLAC DEEP INELASTIC
ELECTRON SCATTERING CROSS-SECTIONS.
Phys.Lett.B282475-482,1992.
34
Provided normalization and shape at lower Q2 for
all DIS experiments- constrain systematic errors
on high energy muon experiments - Perturbative
QCD with and without target mass (TM) effects
35
Current Status of Unpolarised SFs
From Bodek (2000)

• Overall, F2 is well measured over 4 orders of
  magnitude,

36
SLAC E140 and the combined SLAC re-analysis
provided the first precise values and kinematic
dependence of R Related to F2/2xF1 for use by
all DIS experiments to extract F2 from
differential cross section data
R
37
Proton-Antiproton (CDF/Dzero) collisions are
actually parton-parton collisions (free nucleons)
Measure W mass from Transverse mass of electrons
from W decays W-gtelectron-neutrino
38
In 1994 uncertainties in d/u from deuteron
binding effects contributed to an uncertainty in
the W mass (extracted from CDF or Dzero Data of
order 75 MeV. ANOTHER BRICK Wall This is why it
is important to know the nuclear corrections for
PDFs extracted from nucleons bound in Fe
(neutrino) or in Deuterium (d versus u), when the
PDFs are used to extract information from
collider data
Proton-Antiproton (CDF/Dzero) collisions are
actually parton-parton collisions (free nucleons)
By introducing new techniques, CDF data can
provide independent constraints on free nucleon
PDFs. CONSTRAINTS ON PDFS FROM W AND Z RAPIDITY
DIST. AT CDF. AB, Nucl. Phys. B, Proc. Suppl.
79 (1999) 136-138. In Zeuthen 1999, Deep
inelastic scattering and QCD 136-138.
39
E Proton-Antiproton (CDF/Dzero) collisions are
actually parton-parton collisions (free nucleons)
40
Proton-antiproton collisions (CDF)- Measurement
of d/u in the proton by using the W- Asymmetry
Mark Dickson, THE CHARGE ASYMMETRY IN W BOSON
DECAYS PRODUCED IN P ANTI-P COLLISIONS. (1994)
Ph.D.Thesis (Rochester). (now at MIT Lincoln Labs)
Qun Fan, A MEASUREMENT OF THE CHARGE ASYMMETRY IN
W DECAYS PRODUCED IN P ANTI-P COLLISIONS.
Ph.D.Thesis (Rochester 1996) (now at KLA-Tenor
41
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42
Need to measure the W Decay lepton Asymmetry at
high rapidity where there is no central tracking
Unfortunately Ws decay to electrons and
neutrinos - Decay lepton asymmetry is a
convolution of the W production Asymmetry
43
A NEW TECHNIQUE FOR DETERMINING CHARGE AND
MOMENTUM OF ELECTRONS AND POSITRONS USING
CALORIMETRY AND SILICON TRACKING. AB and Q. Fan
In Frascati 1996, Calorimetry in HEP553- 560
(First used in AMY)
Use silicon vertex detector to extrapolate
electron track to the forward shower counters.
Compare the extrapolated location to the centroid
of the EM shower in a segmented shower counter.
Energy of electron determined by the shower
counter, Sign is determined by investigating if
the shower centeroid is to the left or right of
the extrapolated track,
All hadron collider physics (Tevatron, LHC) with
electrons and positrons can be done better
without a central tracker . No Track mis-ID Need
Just silicon tracking and segmented EM HAD
calorimetry -Adapted by CMS-LHC
44
The d/u ratio in standard PDFs found to be
incorrect. Now all new PDF fits include CDF W
Asymmetry as a constraint. PDF error on W mass
reduced to 10 MeV by using current CDF data.
45
With this new technique, one can also
significantly reduce the QCD background for very
forward Z Bosons produced in hadron
colliders. Jinbo Liu, Measurement of d? /dy for
Drell-Yan ee Pairs in the Z Boson Region
Produced in Proton Anti-proton Collisions at 1.8
TeV. UR-1606, 2000 - Ph.D. Thesis (Rochester).
(now at Lucent Technologies) T. Affolder et al.
(CDF- article on Rochester PhD Thesis),
MEASUREMENT OF d? / dY FOR HIGH MASS DRELL-YAN
E E- PAIRS FROM P ANTI-P COLLISIONS AT 1.8-TEV.
Phys.Rev.D63011101,2001.
NLO QCD describes Z -y distributions better than
LO QCD -gt more statistics - Tevatron run II LHC
46
Knowledge of high x PDF is used as input to
searches for new Z bosons in high-mass Drell-Yan
cross sections and Forward-Backward Asymmetry
(another use of forward tracking of
electrons) Arie Bodek and Ulrich Baur
IMPLICATIONS OF A 300-GEV/C TO 500-GEV/C Z-PRIME
BOSON ON P ANTIP COLLIDER DATA AT 1.8-TEV.
Eur.Phys.J.C21607-611,2001 . T. Affolder et
al.(CDF) Measurement of d? / dM and forward
backward charge asymmetry for high mass Drell-Yan
e e- pairs from p anti-p collisions at 1.8-TeV.
Phys.Rev.Lett.87131802,2001
47
Knowing level of PDFs at High x Allows us to
search for New Physics In High Mass Drell Yan
Events Manoj Kumar Pillai, A SEARCH FOR NEW
GAUGE BOSONS IN ANTI-P P COLLISIONS AT 1.8-TEV at
CDF (1996). Ph.D.Thesis (Rochester) Abe et
al.,(CDF) LIMITS ON QUARK - LEPTON COMPOSITENESS
SCALES FROM DILEPTONS PRODUCED IN 1.8-TEV P
ANTI-P COLLISIONS. Phys.Rev.Lett.792198-2203,1
997. Abe et al. (CDF), MEASUREMENT OF Z0 AND
DRELL-YAN PRODUCTION CROSS-SECTION USING DIMUONS
IN ANTI-P P COLLISIONS AT 1.8-TEV.
Phys.Rev.D59052002,1999 Abe et al.(CDF)SEARCH
FOR NEW GAUGE BOSONS DECAYING INTO DILEPTONS IN
ANTI-P P COLLISIONS AT 1.8-TEV.
Phys.Rev.Lett.792192-2197,1997
A few non-discoveries
48
Expected CDF Run II 2 fm-1 Drell Yan Mass
Distribution Need even better PDFs
Expected W Asymmetry 2 fm-1 CDF Rochester PhD
Thesis (in progress)
Expected Z Rapidity 2 fm-1 CDF Rochester PhD
Thesis (in progress) Ji Yeon Han
49
F Phenomenology PUTTING it ALL TOGETHER The
Great Triumph of NNLO QCD Origin of Higher Twist
Effects, d/u and PDFs at large X
NNLO QCD target mass corrections describes all
of DIS data for Q2gt1 GeV2 with NO Need for Higher
Twists. GREAT TRIUMPH for QCD . Most of what was
called low Q2 higher Twist are accounted for by
higher order QCD.
PARTON DISTRIBUTIONS, D/U, AND HIGHER TWIST
EFFECTS AT HIGH X. AB, UK Yang Phys.Rev.Lett.8224
67-2470,1999 . STUDIES OF HIGHER TWIST AND
HIGHER ORDER EFFECTS IN NLO AND NNLO QCD ANALYSIS
OF LEPTON NUCLEON SCATTERING DATA ON F(2) AND R
?(L) / ?(T). AB, UK Yang Eur.Phys.J.C13241-245,20
00
50
NNLO QCDTM black Great Triumph of NNLO QCD.
AB, UK Yang Eur.Phys.J.C13241-245,2000
NNLO QCDTgt Mass works very well for Q2gt1 GeV2
Size of the higher twist effect with NNLO
analysis is very small a2 -0.009 (in NNLO)
versus 0.1( in NLO) - gt factor of 10 smaller,
a4 nonzero
F2P
R
F2D
51
Precision experiment can be done in hadron
colliders, provided we calculate processes higher
orders QCD (e.g. NNLO)
Lots of work for experimentalists - precision
experiments are possible in hadron colliders
(look forward to new results from the LHC)
Lots of work for Theorists - Lots of calculations
are needed in order to get physics out of the data
2000-2004-gt2010 (The high Energy Frontier) For
Tevatron and Run II and LHC , the path to greater
precision is using NNLO QCD fits with both
Q2gt1 GeV2 DIS data very high Q2 Collider
Data.-Good for theorists
52
Great Triumph of NNLO QCD. AB, UK Yang Eur.Phys.J
.C1324,2000 First extraction of (NNLO PDFs)/(NLO
PDFs) ratio
Low x NNLO PDFs 2 higher than NLO PDFs
High x NNLO PDFs 10 lower than NLO PDFs
For High Statistics Hardon Collider Physics (run
II, LHC), the next step is to extract NNLO PDFs.
So declare victory and let theorists and PDF
Professionals (MRST and CTEQ) make progress
towards the next generation NNLO PDF fits for
Tevatron and LHC
53
F2, R comparison of NLO QCDTMHT black
(Q2gt1)(use QCD Renormalons for HT vs NLO
QCDTM only green AB, UK Yang Phys.Rev.Lett.82,199
9
NLO QCD Target Mass Renormalon HT works. A
GREAT QCD TRIUMPH
PDFs and QCD in NLO TM QCD Renormalon Model
for Dynamic HT describe the F2 and R data very
well, with only 2 parameters. Dynamic HT effects
are there but small
54
CONCLUSION Progress is made in finite
incremental steps as new techniques and methods
lead to greater precision (making what was
impossible -gt possible)
A factor of 2 reduction in error each generation
(either statistical or systematic) is worth it,
and one can always go back and re-analyze old
data with better corrections to reduce systematic
errors
In 4 generations of experiments (2)4 16 fold
reduction in statistical errors -reduce
systematics with new techniques
We now have the foundation for making discoveries
(e.g. Higgs) at LHC
2000 Nucleon Structure well understood. NNLO QCD
works from Q21 to the highest values currently
accessible. Hadron colliders are actually quark
and gluon colliders with known and well
understood PDFs.-gt
55
Back to the past (and the future) NEUTRINO SECTOR

• 2000-2004-gt2010 (The Low Energy Frotier)
• Neutrino Oscillations at Low Energy
• 2000-2004 Atmospheric and solar neutrino
  experiments now show evidence for neutrino
  oscillations (small masses and large mixing). An
  emerging new field.-gt Leptogenesis as a source of
  Matter-Antimatter Asymmetry in the Universe?
• However, since the masses are small, the neutrino
  oscillations effects can only be observed be at
  low neutrino energies. In addition, the studies
  require the use of nuclear targets (water, iron,
  carbon)--gt Cry for help

In order to make any advances in this new field,
we need to understand neutrino cross sections and
Nucleon and Nuclear Structure down to Q20 -
Need new foundation
56
Neutrino Cross Sections at Low Energy
sT/E ?

• Quasi-Elastic / Elastic (WM)
• nm n m- p
• Input from both electron and neutrino experiments
  and described by form factors, need axial form
  factor and nuclear corrections
• Resonance (low Q2, Wlt 2)
• nm p m- p p
• Can be well measured in electron scattering, but
  poorly measured in neutrino scattering (fits by
  Rein and Seghal). Need R, axial form factors and
  nuclear corrections
• Deep Inelastic (DIS)
• nm A m- X
• well measured in high energy experiments and
  well described by quark-parton model, but doesnt
  work well at low Q2. Need low Q2 structure
  functions, R, axial structure funct. and nuclear
  corrections

Issues at few GeV

• Resonance scattering and low Q2 DIS contribution
  meet, (How to avoid double counting ?).
• Challenge to describe all these three processes
  at all neutrino (and electron/muon) energies.
  See if model satisfies all known sum rules from
  Q20 to very high Q2
• (Need to understand duality, QCD, low Q2 sum
  rules, transition between DIS and resonance)

57
For Tevatron Run II and LHC, the path to greater
precision is to perform NNLO QCD fits using both
Q2gt1 GeV2 DIS data and very high Q2 Tevatron and
LHC results. In contrast, for applications to
Neutrino Oscillations at Low Energy (down to
Q20) the best approach is to use a LO PDF
analysis (including a more sophisticated target
mass analysis) and include the missing QCD higher
order terms in the form of Empirical Higher Twist
Corrections. Reason For Q2gt1 both Current
Algebra exact sum rules (e.g. Adler sum rule) and
QCD sum rules (e.g. momentum sum rule) are
satisfied. This is why duality works in the
resonance region (so use NNLO QCD analysis) For
Q2lt1, QCD corrections diverge, and all QCD sum
rules (e.g momentum sum rule) break down, and
duality breaks down in the resonance region. In
contrast, Current Algebra Sum rules e,g, Adle sum
rule which is related to the Number of (U minus
D) Valence quarks) are valid.
58
Modified LO Pseudo NNLO approach for low
energiesApplications to Jlab and Neutrino
Oscillations

• Original approach (NNLO QCDTM) was to explain
  the non-perturbative QCD effects at low Q2, but
  now we reverse the approach Use LO PDFs and
  effective target mass and final state masses to
  account for initial target mass, final target
  mass, and missing higher orders

q
mfM (final state interaction)
PM
Resonance, higher twist, and TM
x w
Q2mf2 A
Xbj Q2 /2 Mn
Mn (1(1Q2/n2) )1/2 B
K factor to PDF, Q2/Q2C
MODELING DEEP INELASTIC CROSS-SECTIONS IN THE FEW
GEV REGION. AB, UK Yang Nucl.Phys.Proc.Suppl.1127
0,2002
A initial binding/target mass effect
plus higher order terms B final state mass mf2 ,
Dm2, and photo- production limit (Q2 0)
59
Describes all vector structure functions from
Q20 to 100,000 GeV2
60
Applications to Neutrino Oscillations at Low
Energy
MODELING DEEP INELASTIC CROSS-SECTIONS IN THE FEW
GEV REGION. A. Bodek , U.K. Yang Presented at 1st
Workshop on Neutrino - Nucleus Interactions in
the Few GeV Region (NuInt01), Tsukuba, Japan,
13-16 Dec 2001. Nucl.Phys.Proc.Suppl.11270-76,200
2 e hep-ex/0203009 HIGHER TWIST, XI(OMEGA)
SCALING, AND EFFECTIVE LO PDFS FOR LEPTON
SCATTERING IN THE FEW GEV REGION. A Bodek, U.K.
Yang Proceedings of 4th International NuFact '02
Workshop (Neutrino Factories Workshop on Neutrino
Factories, London, England, 1-6 Jul 2002.
J.Phys.G291899-1906,2003 MODELING NEUTRINO AND
ELECTRON SCATTERING INELASTIC CROSS- SECTIONS IN
THE FEW GEV REGION WITH EFFECTIVE LO PDFS IN
LEADING ORDER. A. Bodek, U.K. Yang . 2nd
International Workshop on Neutrino - Nucleus
Interactions in the Few GeV Region (NUINT 02),
Irvine, California, 12-15 Dec 2002.
Nucl.Phys.Proc.Suppl. hep-ex/0308007 Invited
Article to be published in Annual Review of
Particle and Nuclear Science 2005
61
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64

• 2000-2004-gt2010 (The Low Energy Frotier)
• Vector Part well understood - Phenomenology
  ABU K Yang (2002-2004)
• However, need more data on F2 and R in the
  resonance region for both axial and vector
  scattering
• 2004-2005 (JUPITER, e-N at Jlab) - Collaborative
  effort between HEP and Nuclear Physics
  communities - Approved January 2004

• - Axial Structure Function also need to be
  measured in the next Generation NUMI Neutrino
  beam -
• 2005-2008 MINERvA, v-N at Fermilab)- Also
  Collaborative effort between HEP and Nuclear
  Physics communities - Approved March 2004.

65
Maintaining the colorful QCD Program
G JUPITER at Jlab (Bodek - Rochester,Keppe-
Hampton, Spokespersons) will provided
electron-Carbon (also e-H and e-D and other
nuclei such as e-Fe) data in resonance region,
and final states (Manly-Rochester)-summer 05.
MINERvA at FNAL (McFarlandRochester, Morfin
-Fermilab) will provide Neutrino-Carbon data at
low energies. Needed in order to investigate the
electroweak sector at low mass (neutrino
oscillations) G CDF Run II (now) and CMS-LHC,
high statistics Ws Zs and Drell Yan - Precise
PDFs to investigate the electroweak sector at
high mass (Top, Higgs)
66
Additional Slides
67

• Time Line Several Parallel Program
  over 30 years
• Electron scattering e-P, e-N, e-A (Kendal
  Friedman Taylor- Panofsky Nobel Prizes)
• Electron Scatt. SLAC-MIT SLAC E49,
  E87more(1967-1973) A --------- D
• Electron Scatt. SLAC E139, E140, E140x,E141, NE8
  (1983-1993) D
• New Electron Scatt. JUPITER Expt at Jefferson Lab
  (2004-now G)
• Hadron Expt. p-Fe, pion-Fe and p-pbar, p-p
  colliders
• E379/E595 Hadronic Charm Production at Fermilab
  (1974-1983) B
• CDF proton-antiproton Expt at Fermilab
  (1988---E----now)
• Develop segmented tile-fiber
  and strip-fiber calorimetry ( 1990------2004)
• CMS Experiment at CERN LHC
  (1995-----now)
• Neutrino Experiments (Frank Sciulli Panofsky
  Prize)
• The CCFR-NuTeV Neutrino Expt at Fermilab
  (1974------- C-------2004)
• New MINERvA Neutrino Expt at Fermilab
  (2004-now G)
• Phenomenology (1999-F-now)
• ee- Experiments
• The AMY ee- Collaboration at TRISTAN/KEK JAPAN
  (1982-1990) skip
• A lot of fun, but mostly unrelated to nucleon
  structure except measurement of ?S
• And Shower Electron tracking with with segmented
  calorimetry

68
"Physics is generally paced by technology and not
by the physical laws. We always seem to ask more
questions than we have tools to answer. Wolfgang
K. H. Panofsky

• 2004 Arie Bodek (Rochester)
• 2003 William Willis (Columbia)
• 2002 Kajita Takaaki, Masatoshi Koshiba and
  Yoji Totsuka
• 2001 Paul Grannis (SUNY SB)
• Martin Breidenbach (SLAC)
• 1999 Edward H. Thorndike (Rochester)
• 1998 David Robert Nygren (Berkeley)
• 1997 Henning Schroder and Yuri Zaitsev
• 1996 Gail G. Hanson and Roy F. Schwitters
• 1995 Frank J. Sciulli (Columbia)
• 1994 Thomas J. Devlin (Rutgers)
• and Lee G Pondrom (Wisconsin)

It is an honor to be associated with these
previous Panofsky Prize Winners 1993 Robert B.
Palmer, Nicholas P. Samios, and Ralph P. Shutt
1992 Raymond Davis, Jr. and Frederick Reines
1991 Gerson Goldhaber and Francois Pierre
1990 Michael S. Witherell (Santa Barbara) 1989
Henry W. Kendall, Richard E. Taylor, and Jerome
I. Friedman (MIT/SLAC) 1988 Charles Y. Prescott
(SLAC)